package com.tomatozq163.structure;

public class Array<E> {
    private E[] data;
    private int size;

    public Array(int initCapacity) {
        //不能直接 new E[]
        data = (E[])(new Object[initCapacity]);
        size = 0;
    }

    public Array(){
        this(10);
    }

    public int getSize(){
        return size;
    }

    public int getCapacity(){
        return data.length;
    }

    public boolean isEmpty(){
        return size == 0;
    }

    public void addLast(E e){
        add(size,e);
    }

    public void add(int index,E e) {
        if (size==getCapacity())
            resize(getCapacity()*2);

        if (index<0 || index>size)
            throw new IllegalArgumentException("Add failed.Require index>=0 and index<=size");

        for (int i=size - 1;i>=index;i--) {
            data[i+1] = data[i];
        }

        data[index] = e;
        size++;
    }

    public void addFirst(E e) {
        add(0,e);
    }

    @Override
    public String toString(){
        StringBuilder res = new StringBuilder();
        res.append(String.format("Array:size=%d,capacity=%d\n",size,data.length));
        res.append("[");

        for (int i = 0; i < size; i++) {
            res.append(data[i]);

            if(i!=size-1){
                res.append(",");
            }
        }

        res.append("]");

        return res.toString();
    }

    public E get(int index){
        if (index<0 || index>=size) {
            throw new IllegalArgumentException("Get failed.Index is illegal.");
        }

        return data[index];
    }

    public void set(int index,E e){
        if (index<0 || index>=size) {
            throw new IllegalArgumentException("Get failed.Index is illegal.");
        }

        data[index] = e;
    }

    public boolean contains(E e){
        for (int i = 0; i < size; i++) {
            if ( data[i].equals(e))
                return true;
        }

        return false;
    }

    public int find(E e){
        for (int i = 0; i < size; i++) {
            if ( data[i].equals(e))
                return i;
        }

        return -1;
    }

    public E remove(int index){
        if (index<0 || index>=size) {
            throw new IllegalArgumentException("Get failed.Index is illegal.");
        }

        E ret = data[index];

        for (int i = index  ; i < size ; i++) {
            data[i] = data[i+1];
        }

        size--;

        if(size == getCapacity()/4 && getCapacity()/2 !=0){
            resize(getCapacity()/2);
        }

        data[size] = null;

        return ret;
    }

    public void removeElement(E e){
        int index = find(e);

        if (index!=-1){
            remove(index);
        }
    }

    public E removeFirst(){
        return remove(0);
    }

    public E removeLast(){
        return remove(size - 1);
    }

    public void resize(int newCapacity){
        E[] newData = (E[])(new Object[newCapacity]);

        for (int i = 0; i < Math.min(getCapacity(),newCapacity); i++) {
            newData[i] = data[i];
        }

        data = newData;
    }

    public E getLast() {
        return get(getSize() - 1);
    }

    public static void main(String[] args){
        Array<Integer> arr = new Array<>(5);

        for (int i = 0; i < 10; i++) {
            arr.addLast(i);
        }

        System.out.println(arr);

        arr.add(1,100);

        System.out.println(arr);

        arr.addFirst(-1);

        System.out.println(arr);

        arr.remove(2);
        System.out.println(arr);
    }
}